Lithium-sulfur batteries (Li/S) are considered one of the most promising candidates to replace conventional Lithium-ion (Li-ion) batteries. Li—S batteries perform better with significantly higher specific density, theoretically 2600 Wh/kg. Li-ion batteries have a theoretical 430 Wh/kg capacity, typically 120 Wh/kg practically. Additionally, Li—S batteries have an operating voltage of 2.1 V at the second lower voltage plateau, suitable for low voltage electronic devices. Economically, these batteries have significantly lower costs, as sulfur is much less expensive than the transitional metals used in current Li-ion batteries.
However, in practice, these batteries face serious problems of low active material utilization and poor rechargeability, due to the insulating nature of sulfur and solid reduction products, also referred to as the polysulfide redox shuffle. Further, there is a loss of active material in the form of insoluble polysulfide reaction products. Current research efforts have been mostly focused on the protection of the lithium anode from reactions with the polysulfide and suppression of the diffusion of dissolved polysulfide out of the cathode.